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Study of the Isospin Symmetry in 60 Zn

Dedicated to PF. Study of the Isospin Symmetry in 60 Zn. Giulia Gosta University of Milan and INFN. Supervisor: Franco Camera Assistant Supervisor: Angela Bracco. Outline. The isospin symmetry and its breaking The experiment Preliminary analysis and first results

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Study of the Isospin Symmetry in 60 Zn

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  1. Dedicated to PF Study of the Isospin Symmetry in 60Zn Giulia Gosta University of Milan and INFN Supervisor: Franco Camera Assistant Supervisor: Angela Bracco

  2. Outline • The isospin symmetry and its breaking • The experiment • Preliminary analysis and first results • Isospin breaking beyond nuclear structure • Conclusion End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  3. The isospin symmetry Based on two assumption related to the nuclear interaction: Iz = ½ • Charge symmetry : • n-n interaction is the same as p-p interaction I = ½ Iz = (N-Z)/2 Iz < I < (N+Z)/2 n N g.s. I=Iz p • Charge independence : n-p interaction is also the same Iz = - ½ In N=Z nuclei I = Iz=0 End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  4. Isospin SymmetryBreaking The Coulomb interaction (that is much weaker than the nuclear interaction) breaks the Isospin symmetry inducing a mixing between state with different Isospin End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  5. Isospin SymmetryBreaking The Coulomb interaction (that is much weaker than the nuclear interaction) breaks the Isospin symmetry inducing a mixing between state with different Isospin Ground State End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  6. Isospin SymmetryBreaking The Coulomb interaction (that is much weaker than the nuclear interaction) breaks the Isospin symmetry inducing a mixing between state with different Isospin Perturbative approach Isovector part of the Coulomb potential Mixing probability in the g.s. Ground State Becomes important between states closed in energy End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  7. Isospin SymmetryBreaking How muchisit? α2 vs E* ? The Coulomb interaction (that is much weaker than the nuclear interaction) breaks the Isospin symmetry inducing a mixing between state with different Isospin Perturbative approach Isovector part of the Coulomb potential Mixing probability in the g.s. Ground State Becomes important between states closed in energy End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  8. Compound nuclei Compound nuclear reactions take place when a projectile is captured, creating a compound nucleus in an excited energy state which subsequently decays. End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  9. ... In compound nuclei Coulomb Spreading width : weak E* dependence Compound nucleus decay width: strong E* dependence End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  10. ... In compound nuclei Coulomb Spreading width : weak E* dependence Compound nucleus decay width: strong E* dependence Morinaga’s hypothesis (1955): Isospin becomes a better symmetry as excitation energy increases. End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  11. How can we measure it ? Electric dipole transition (E1) Electric (ΔS=0) and isovector (ΔI=1), the strenght is concentrated in the Giant Dipole Resonance End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  12. How can we measure it ? Electric dipole transition (E1) Electric (ΔS=0) and isovector (ΔI=1), the strenght is concentrated in the Giant Dipole Resonance NO MIXING I=0 I=1 I=0 End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  13. How can we measure it ? Electric dipole transition (E1) Electric (ΔS=0) and isovector (ΔI=1), the strenght is concentrated in the Giant Dipole Resonance NO MIXING I=0 I=1 I=0 End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  14. How can we measure it ? Electric dipole transition (E1) Electric (ΔS=0) and isovector (ΔI=1), the strenght is concentrated in the Giant Dipole Resonance NO MIXING I=0 I=1 I=0 End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  15. How can we measure it ? Electric dipole transition (E1) Electric (ΔS=0) and isovector (ΔI=1), the strenght is concentrated in the Giant Dipole Resonance NO MIXING I=0 I=1 I=0 Inhibition of γ-decay (few I=1 states) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  16. How can we measure it ? Electric dipole transition (E1) Electric (ΔS=0) and isovector (ΔI=1), the strenght is concentrated in the Giant Dipole Resonance MIXING NO MIXING I=0 I=0 I=1 + I=1 I=0 I=1 I=0 Inhibition of γ-decay (few I=1 states) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  17. How can we measure it ? Electric dipole transition (E1) Electric (ΔS=0) and isovector (ΔI=1), the strenght is concentrated in the Giant Dipole Resonance MIXING NO MIXING I=0 I=0 I=1 + I=1 I=0 I=1 I=0 Inhibition of γ-decay (few I=1 states) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  18. How can we measure it ? Electric dipole transition (E1) Electric (ΔS=0) and isovector (ΔI=1), the strenght is concentrated in the Giant Dipole Resonance MIXING NO MIXING I=0 I=0 I=1 + I=1 I=0 I=1 I=0 Inhibition of γ-decay (few I=1 states) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  19. How can we measure it ? Electric dipole transition (E1) Electric (ΔS=0) and isovector (ΔI=1), the strenght is concentrated in the Giant Dipole Resonance MIXING NO MIXING I=0 I=0 I=1 + I=1 I=0 I=1 I=0 Inhibition of γ-decay (few I=1 states) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  20. How can we measure it ? Electric dipole transition (E1) Electric (ΔS=0) and isovector (ΔI=1), the strenght is concentrated in the Giant Dipole Resonance MIXING NO MIXING I=0 I=0 I=1 + I=1 I=0 I=1 I=0 Inhibition of γ-decay (few I=1 states) The observed E1 strenght is a signature of the mixing End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  21. The experiment June 2016 @Laboratori Nazionali di Legnaro-INFN Ceruti et al. & Corsi at al. D. Mondal et al. 32S + 28Si 60Zn* We form a I=0 Compound Nucleus by fusion-evaporation reaction: Satula et al., PRL 103 (2009) This work (N=Z N=Z N=Z) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  22. The experiment June 2016 @Laboratori Nazionali di Legnaro-INFN Ceruti et al. & Corsi at al. D. Mondal et al. 32S + 28Si 60Zn* We form a I=0 Compound Nucleus by fusion-evaporation reaction: Satula et al., PRL 103 (2009) This work (N=Z N=Z N=Z) We form a I0 Compound Nucleus by fusion-evaporation reaction: 32S + 30Si 62Zn* (N=Z N≠Z N ≠ Z) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  23. The experiment June 2016 @Laboratori Nazionali di Legnaro-INFN Ceruti et al. & Corsi at al. D. Mondal et al. 32S + 28Si 60Zn* We form a I=0 Compound Nucleus by fusion-evaporation reaction: Satula et al., PRL 103 (2009) This work (N=Z N=Z N=Z) We form a I0 Compound Nucleus by fusion-evaporation reaction: the mixing effect in 62Zn should not be practically evident 32S + 30Si 62Zn* (N=Z N≠Z N ≠ Z) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  24. The experiment June 2016 @Laboratori Nazionali di Legnaro-INFN The γ-rays yield from the E1 decay of the GDR built on the CN was measured. From the data fit α2 can be extracted. Ceruti et al. & Corsi at al. D. Mondal et al. 32S + 28Si 60Zn* We form a I=0 Compound Nucleus by fusion-evaporation reaction: Satula et al., PRL 103 (2009) This work (N=Z N=Z N=Z) We form a I0 Compound Nucleus by fusion-evaporation reaction: the mixing effect in 62Zn should not be practically evident 32S + 30Si 62Zn* T1 = 2.0 MeV (E*= 47 MeV) T2 = 2.4 MeV (E*= 58 MeV) (N=Z N≠Z N ≠ Z) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  25. Array of 10 LaBr3:Ce crystals • (at 70° at 20 cm from the target) • for the measurement of high-energy γ rays. • GALILEOarray of • 25 HPGe detectors • for the measurement of low-energy γ rays The experimental setup End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  26. Array of 10 LaBr3:Ce crystals • (at 70° at 20 cm from the target) • for the measurement of high-energy γ rays. • GALILEOarray of • 25 HPGe detectors • for the measurement of low-energy γ rays The experimental setup • Ancillary detectors: • EUCLIDES (array of 40 ∆E-E Si telescopes) • Neutron Wall (array of 15 liquid scintillators BC-501A) Used to tuning in a more accurate way the statistical model trough the analysis of the compound nuclei residues population End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  27. Pre-analysis 11B + D -> 13C* (up to 15.1 MeV) • Energy Calibration • LaBr3:Ce • Linear calibration at low energy (using standard sources) • Quadratic calibration at high energy (in beam calibration) • HPGe • Up to 5 order polynomial curves (using standard sources) • Time calibration LaBr3:Ce • Time alignment • Time walk correction • Time drift correction End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  28. Pre-analysis 11B + D -> 13C* (up to 15.1 MeV) • Energy Calibration • LaBr3:Ce • Linear calibration at low energy (using standard sources) • Quadratic calibration at high energy (in beam calibration) • HPGe • Up to 5 order polynomial curves (using standard sources) • Time calibration LaBr3:Ce • Time alignment • Time walk correction • Time drift correction End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  29. Pre-analysis 11B + D -> 13C* (up to 15.1 MeV) • Energy Calibration • LaBr3:Ce • Linear calibration at low energy (using standard sources) • Quadratic calibration at high energy (in beam calibration) • HPGe • Up to 5 order polynomial curves (using standard sources) • Time calibration LaBr3:Ce • Time alignment • Time walk correction • Time drift correction End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  30. Pre-analysis 11B + D -> 13C* (up to 15.1 MeV) • Energy Calibration • LaBr3:Ce • Linear calibration at low energy (using standard sources) • Quadratic calibration at high energy (in beam calibration) • HPGe • Up to 5 order polynomial curves (using standard sources) • Time calibration LaBr3:Ce • Time alignment • Time walk correction • Time drift correction End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  31. Pre-analysis 11B + D -> 13C* (up to 15.1 MeV) • Energy Calibration • LaBr3:Ce • Linear calibration at low energy (using standard sources) • Quadratic calibration at high energy (in beam calibration) • HPGe • Up to 5 order polynomial curves (using standard sources) • Time calibration LaBr3:Ce • Time alignment • Time walk correction • Time drift correction End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  32. Gate on time peak 32S+ 30Si 62Zn* (T=2,4 MeV) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  33. Gate on time peak 32S+ 30Si 62Zn* (T=2,4 MeV) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  34. Gate on time peak 32S+ 30Si 62Zn* (T=2,4 MeV) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  35. Gate on time peak 32S+ 30Si 62Zn* (T=2,4 MeV) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  36. Gate on time peak 32S+ 30Si 62Zn* (T=2,4 MeV) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  37. Gate on time peak GDR 32S+ 30Si 62Zn* (T=2,4 MeV) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  38. Compare with statistical model Preliminary End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  39. Compare with statistical model Γ = 10keV Preliminary End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  40. Isospin Mixing beyond nuclear structure The Cabibbo–Kobayashi–Maskawa matrix, CKM matrix contains information on the strength of the flavor-changing weak interaction. β decay is an example of a weak decay, governed by the fisrt term of the CKM matrix Vud. A quark u change in a quark d (or viceversa) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  41. Super-allowed Fermi transitions are excellent probes for testing properties of weak interaction. A «corrected» value Ftis defined as: Radiative correction I.S. Towner and J.C. Hardy PRC 82, 065501 (2010) Isospin symmetry breaking correction End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  42. Conclusion • Isospin symmetry was introduced in order to simplify the description of the nucleus • Coulomb interaction breaks the symmetry • In certain conditions the approximation is valid, in other the effect is not negligible • This study is relevant also beyond the nuclear structure End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  43. Thank you for your attention…

  44. ... In compound nuclei Coulomb spredingwidth of the IsobaricAnalog State (Form Data) Colo’ et al .PRC 54(1996) M.N. Harakeh et al. Phys. Lett. B 176(1986)297 A.Behr et al. Phys. Rev. Lett. 70(1993)3201 Sagawa et al Physics Letters B 444 1998. 1–6 Satula et al PRL 103, 012502 (2009) Width of the nonopole resonance at the energy of IAS (Parameter) Decaywidthof the nucleus(From CN decay) Γ (T) = Γ (T=0)*(1+cT) Should be determined trough a microscopic calculation End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  45. 32S+ 30Si 62Zn* (T=2,4 MeV) Time-walk and drift correction End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  46. Time of flight teqnique γ-peak Gamma rays Target Slow Neutron LaBr3:Ce Fast Neutrons n-peak Counts (log scale) Time (ns) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  47. Compound nucleus decay E= 31.2 A-1/3 +20.6A-1/6 Giant Dipole Resonance Eγ ~ 15 MeV FWHM ~ 5-7 MeV Pγ/Ppart≈ 10-3 γ-decay below n-threshold Eγ < 8 MeV FWHM ~ 2-10 keV Mγ ~ 20-30 (within few ps) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  48. Statistical Model Tuning: 2. Residual nuclei 43Sc 51Mn 46Ti 57Co 56Co 45Ti 54Fe 60Zn T=2,4 MeV End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  49. Previousresults: Isospin mixing in 80Zr 40Ca + 40Ca 80Zr* α2 (T=0)=(4.6±0.9)% S.Ceruti et al. PRL 115, 222502 (2015) A.Corsi et al. PRC 84, 041304(R) (2011) • Γ↓does not change with T • α2 is larger at T = 2 MeV • Γ↓=12±3 keV, α2=0.046±0.007 • Γ↓=10±3 keV, α2=0.013±0.004 T ≈ 2 MeV T ≈ 3 MeV End First-Year of the PhD students: Workshop 2018 Giulia Gosta

  50. Super-allowed Fermi • Measurement of ß-particleanisotropyemission • Difficult for veryunstable nuclei ƒt depends only on universal quantities, should be mass independent ! Partial half-life of transition Vectorcouplingconstant (from semi-leptonic weak interction) I.S. Towner and J.C. Hardy PRC 82, 065501 (2010) Weak interaction coupling constant Fermi Matrix element ƒt Gv Vud δC is not directly measurable Auerbach proposed the following parametrization: I.S. Towner and J.C. Hardy PRC 82, 065501 (2010) Isospin mixing N.Auerbach, PRC 79, 035502 (2009) End First-Year of the PhD students: Workshop 2018 Giulia Gosta

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